Good news: Civilization less likely to end from an asteroid collision

There are lots of good reasons to worry about the sustainability of modern civilization, but you can drop a killer asteroid a bit down the list thanks to some new findings.

New observations by NASA’s Wide-field Infrared Survey Explorer, or WISE, find there are significantly fewer near-Earth asteroids in the mid-size range than previously believed.

There are at least 40 percent fewer near-Earth asteroids that previously thought. (NASA/JPL-Caltech)

Astronomers using WISE say they believe there are now about 19,500 mid-size asteroids — between 330 and 3,300 feet across — near Earth. That’s a considerable drop from previous guesses of 35,000. These mid-size asteroids are large enough to cause regional catastrophes.

Additionally, the space agency says it has now found 93 percent of the largest asteroids near Earth, those which are larger than 3,300 feet across. It’s generally believed that an asteroid larger than about 6,000 feet would cause a global catastrophe.

So we’ve found nearly all the big ones that could end civilization as we know it, and there are fewer of the mid-size asteroids capable of causing widespread devastation than previously thought.

The WISE instrument scans the entire sky in infrared light, allowing it to see the coolest stars, the universe’s most luminous galaxies and some of the darkest near-Earth asteroids and comets.

It’s useful for pinning down the size of asteroids because, unlike with visible light, in the infrared part of the spectrum the brightness of an object is directly related to its size.